The necropolis is a complex of several domus de janas ("fairy houses"), a series of Neolithic tombs dug inside rock. The crown jewel of the site is the main one. Formerly a tomb complex, it was then re-used in Roman times, with modifications, and then as a Church until the middle ages, with even more alterations and decorations.

Besides the fact that it is literally dug in stone, what makes the "building" unique is that every single stage of the monument is still visible. From the Neolithic red plaster, to the Roman frescoes, to the more recent (but still Palaeochristian) well-preserved paintings, depicting the apostles and scenes from the life of Jesus. The structure of the tomb itself has been heavily altered to fit the later purposes, but the overall design remains almost intact.

Some of the other tombs may also be visited, but they aren't as decorated. Above the structure there are a few other Neolithic monuments.